The invention of the world’s first white laser, which could revolutionize communications, lighting and displays, is being recognized as one of the top 100 breakthroughs of the year by Popular Science magazine.
Arizona State University electrical engineering professor Cun-Zheng Ning worked on the problem for 10 years until he and his team of graduate students cracked it.
The white laser will eventually produce computer and TV displays with 70 percent more colors than current technology.
Laser TVs exist now, but they are bulky, heavy and extremely expensive. And, without the white laser, they haven’t reached their full potential.
It will take some time for the technology to advance to the consumer level, Ning said.
“It’s basic research at this point,” he said. “The lasers are still quite big, and the projection is not like an LCD TV we have at home. … We cannot produce multicolor white lasers that efficiently, so that we can put in our TV pixels.”
Composition-graded nanostructures on a single quartz substrate. a, Real color image of the as-grown full composition-grade sample under ambient lighting. The light grey and black regions on the substrate represent the ZnSand CdSe-rich compositions, respectively and the intermediate colors are associated with the quaternary alloys of intermediate compositions. Scale bar only for the width direction, 0.25cm. b and c, PL images of the region between the dashed lines under 10X (b) and 50X (c) of magnification . The sample was pumped by a 405 nm continuous wave (CW) laser diode. d, Cross-sectional SEM images from six representative points along the substrate, within the region between the dashed lines in a. Scale bars, 10m. e, EDS results from fourteen evenly-spaced points between the dashed lines in a, moving from left (ZnS-rich) to right (CdSe-rich). f, Corresponding EDS spectra of several points in e.
Li-Fi is a bidirectional, high speed and fully networked wireless communication technology similar to Wi-Fi. Li-Fi is a subset of optical wireless communications (OWC) and can be a complement to RF communication (Wi-Fi or Cellular network), or a replacement in contexts of data broadcasting.
LED based Li-Fi should be able to get hundreds of megabit per second communication speed. White Laser based Li-Fi should be able to get hundreds of times faster than LED based Li-Fi.
Abstract – monolithic white laser
Monolithic semiconductor lasers capable of emitting over the full visible-colour spectrum have a wide range of important applications, such as solid-state lighting, full-colour displays, visible colour communications and multi-colour fluorescence sensing. The ultimate form of such a light source would be a monolithic white laser. However, realizing such a device has been challenging because of intrinsic difficulties in achieving epitaxial growth of the mismatched materials required for different colour emission. Here, we demonstrate a monolithic multi-segment semiconductor nanosheet based on a quaternary alloy of ZnCdSSe that simultaneously lases in the red, green and blue. This is made possible by a novel nanomaterial growth strategy that enables separate control of the composition, morphology and therefore bandgaps of the segments. Our nanolaser can be dynamically tuned to emit over the full visible-colour range, covering 70% more perceptible colours than the most commonly used illuminants.